1. Field of the Invention
This invention relates in general to the infusion of intravenous (IV) solutions. In particular, the invention relates to portable IV infusion pumps for use by ambulatory and other patients.
2. Description of the Related Art
Infusion pumps are used to deliver various types of solutions intravenously to patients. A variety of drugs are commonly administered to patients by means of the intravenous solutions. Among the types of therapies requiring this kind of administration are chemotherapy, antibiotic therapy and antiviral therapy. In many cases, patients receive multiple daily therapies. Certain medical conditions require infusions of drugs in solution over relatively short periods such as from 30 minutes to two hours. Infusion pumps have been developed in the prior art in an effort to meet these needs. There has been a requirement of providing portable infusion pumps for use by ambulatory patients and the like.
The different types of infusion pumps in the prior art include elastomeric pumps which squeeze the solution from flexible containers, such as balloons, into IV tubing for delivery to the patient. Spring-loaded pumps have also been provided to pressurize the solution containers or reservoirs. In certain pump designs cartridges containing flexible compartments that are squeezed by pressure rollers for discharging the solutions are provided, such as in U.S. Pat. No. 4,741,736. U.S. Pat. No. 5,330,431, issued to the inventor of the present invention, shows an infusion pump in which standard pre-filled single dosage IV bags are squeezed by the use of a roller. U.S. Pat. No. 5,348,539, also issued to the inventor of the present invention, shows an infusion pump in which prepackaged IV bags are squeezed by a bladder which is actuated by fluid pumped from a reservoir. In such a design, a relatively large volume of fluid must be pumped into the bladder to fully empty the IV bag. This requires a relatively larger sized pump and fluid reservoir, which results in a larger sized unit. The need has been recognized for an infusion pump which is smaller and more compact so that it can be better adapted for mobile use by ambulatory and other patients.